Add a "fork" of musl as //fusl.

fusl/src/string/strcpy.c

Index: fusl/src/string/strcpy.c
diff --git a/fusl/src/string/strcpy.c b/fusl/src/string/strcpy.c
new file mode 100644
index 0000000000000000000000000000000000000000..f7e3ba38c16e3e69395f85dcdd6c23bb20797a6c
--- /dev/null
+++ b/fusl/src/string/strcpy.c
@@ -0,0 +1,16 @@
+#include <string.h>
+
+char *__stpcpy(char *, const char *);
+
+char *strcpy(char *restrict dest, const char *restrict src)
+{
+#if 1
+	__stpcpy(dest, src);
+	return dest;
+#else
+	const unsigned char *s = src;
+	unsigned char *d = dest;
+	while ((*d++ = *s++));
+	return dest;
+#endif
+}